Embodiments of the invention generally relate to the ion exchange technology, and more particularly, to an ion-exchange device utilizing ion-exchange materials and a regeneration method of the ion exchange materials.
Ion exchange materials are used to remove or replace dissolved solids, ions or other charged species in solutions, for example, for producing high purity water, for deionization of waste water, or for water softening. Ion exchange materials typically comprises two types, namely cation-exchange and anion-exchange material, both types generally being solids or gels which comprise replaceable ions, or which chemically react with specific ions in the solution.
When the ion exchange materials are saturated with ions extracted from the source solution, the ion exchange materials can not perform ion exchanging any more, or results in a low efficiency of ion exchanging. Accordingly, ion exchange materials need to be regenerated to remove the extracted ions from the ion exchange materials. One convention regeneration method of ion exchange materials is a chemical method which has a rinsing step using acidic solutions or concentrated salt solution (e.g saturated sodium chloride solution) for cation-exchange material and basic solutions for anion-exchange material to replace the extracted ions. However, in order to have a complete regeneration of the ion exchange materials, the acidic solutions and basic solutions usually include excessive ions, which result in a waste acid or a waste base, which is considered to be hazardous waste and requires additional treatment before discharge to the environment. Another conventional regeneration method of ion exchange materials is an electrochemical method which splits water into H+ and OH− under DC current and then regenerating the ion exchange materials by the H+ and OH−. Similar to that discussed with respect to the chemical method, in order to have a complete regeneration of the ion exchange materials, the produced H+ and OH− are generally excessive, and result in a waste acid or a waste base. In addition, the electrolysis or water splitting process consumes a considerably large electricity due to the low efficiency of electrochemical water splitting.
In a word, the conventional ion exchange resin regeneration methods are not efficient and costly. It may be desirable to have an ion exchange device and a regeneration method that differs from those conventional assemblies and methods.